Trichostema dichotomum
| Trichostema dichotomum | |
|---|---|
| |
| Photo taken by Gil Nelson | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Magnoliophyta – Flowering plants |
| Class: | Magnoliopsida – Dicotyledons |
| Order: | Lamiales |
| Family: | Lamiaceae ⁄ Labiatae |
| Genus: | Trichostema |
| Species: | T. dichotomum |
| Binomial name | |
| Trichostema dichotomum L. | |
| |
| Natural range of Trichostema dichotomum from USDA NRCS Plants Database. | |
Common name: forked bluecurls
Contents
Taxonomic notes
Description
"Pubescent annual or weak perennial herbs from tap roots, freely branched with opposite branches. Stems obscurely angled, usually stipitate-glandular, leafy. Leaves entire or toothed, rarely lobed, petiolate to essentially sessile. Inflorescence a panicle of paired, bracteate, helicoid cymes with a flower at the axis of each pair; bracts similar to the leaves, smaller. Calyx bilabiate, lower lip longer than the upper with 3 essentially equal teeth, upper with 2 similar teeth; corolla blue to violet, zygomorphic, 5-lobed, lowest lobe lip-like, 5-10 mm long, lateral triangular-ovate, 2-4 mm long, tube short. Stamens 4, ca. 2X as long as the corolla, curved between the lateral lobes and curled downward almost meeting the lip; stigma bilobed, style curled in same fashion as stamens. Mericarps brownish to olive or blackish, dull, obovoid." - Radford et al 1964
"At least the principal stems spreading pubescent, the trichomes 0.2-1 mm long, usually bearded at the nodes. Leaves elliptic to elliptic-lanceolate, 2-7 cm long, 0.4-2.3 cm wide, entire, crenate, or rarely loved, base tapered to cuneate or attenuate; petioles 0-1.5 cm long. Mericarps distinctly reticulate, 1.9-2.3 mm long." - Radford et al 1964
Distribution
Ecology
Habitat
In the Coastal Plain in Florida and Georgia, T. dichotomum has been found in burned upland pinewoods; longleaf pine forests; annually burned pine savannas; loamy sand of woodlands; loamy sand of open pine-hickory woods; floodplain forests; sandy loam along bluffs; amidst cypress knees on the shores of lakes and ponds; sandy ridges; burned pond pine shrub bog flatwoods; longleaf pine-turkey oak sand ridges; and at the edges of an open limestone glade (FSU Herbarium). It has been recorded in disturbed habitats such as roadsides; deciduous flatwoods clearings; and a mowed meadow. Associated species include Vaccinium stamineum, Trichostema setaceum, Scoparia, Panicum, Andropogon gerardii, Angelica dentata, and Helianthus radula (FSU Herbarium).
Phenology
It has been recorded flowering September and October, and fruiting September through December (FSU Herbarium).
Seed dispersal
According to Kay Kirkman, a plant ecologist, this species disperses by gravity. [1]
Seed bank and germination
Habitats associated with high light levels and large diurnal temperature fluctuations near tortoise mounds are probably favorable for the establishment of T. dichotomum. [2]
Fire ecology
Pollination
The following Hymenoptera families and species were observed visiting flowers of Trichostema dichotomum at Archbold Biological Station (Deyrup 2015):
Halictidae: Lasioglossum placidensis
Use by animals
It was found to be one of the most common spring recruits on recently abandoned tortoise mounds (Kaczor and Hartnett 1990).
Bee species, Caupolicana electa and Dialictus placidensis, have been observed on T. dichotomum (Deyrup 2012).
Diseases and parasites
Conservation and Management
Cultivation and restoration
Photo Gallery
References and notes
Bazzaz, F. A. 1979. The physiological ecology of plant succession. Annu. Rev. Ecol. Syst., 10:351- 371.
Deyrup, M.A. and N.D. 2015. Database of observations of Hymenoptera visitations to flowers of plants on Archbold Biological Station, Florida, USA.
Deyrup, M. and L. Deyrup (2012). "The diversity of insects visiting flowers of saw palmetto (Arecaceae)." Florida Entomologist 95(3): 711-730.
Florida State University Robert K. Godfrey Herbarium database. URL: http://herbarium.bio.fsu.edu. Last accessed: July 2015. Collectors: Loran C. Anderson, Robert K. Godfrey, R. Komarek, R. A. Norris, Andre F. Clewell, K. Craddock Burks, David Dixon, O. Lakela, R. Kral, James P. Gillespie, R. L. Lazor, A. H. Curtiss, Roy Jervis, John B. Nelson, R. E. Perdue, Jr., Richard S. Mitchell, Bian Tan, Nancy E. Jordan, Ann F. Johnson, Wilson Baker, Cecil R Slaughter, Marc Minno. States and Counties: Florida: Baker, Calhoun, Citrus, Columbia, Duval, Franklin, Gadsden, Gulf, Jackson, Jefferson, Lafayette, Leon, Liberty, Madison, Okaloosa, Wakulla, Walton. Georgia: Grady, Thomas. Compiled by Tall Timbers Research Station and Land Conservancy.
Kaczor, S. A. and D. C. Hartnett (1990). "Gopher tortoise (gopherus polyphemus) effects on soils and vegetation in a Florida sandhill." American Midland Naturalist 123: 100-111.
Radford, Albert E., Harry E. Ahles, and C. Ritchie Bell. Manual of the Vascular Flora of the Carolinas. 1964, 1968. The University of North Carolina Press. 897. Print.
